StreamBuilder<CompassXEvent>(
  stream: CompassX.events,
  builder: (context, snapshot) {
    if (!snapshot.hasData) return const Text('No data');
    final compass = snapshot.data!;
    return Column(
      mainAxisSize: MainAxisSize.min,
      children: [
        Text('Heading: ${compass.heading}'),
        Text('Accuracy: ${compass.accuracy}'),
        Text('Should calibrate: ${compass.shouldCalibrate}'),
        Transform.rotate(
          angle: compass.heading * math.pi / 180,
          child: Icon(
            Icons.arrow_upward_rounded,
            size: MediaQuery.of(context).size.width - 80,
          ),
        ),
      ],
    );
  },
),

• heading: The heading relative to true north in degree.
• accuracy: The accuracy of the sensor data.
• shouldCalibrate: Whether the sensor should be calibrated or not.

$ flutter pub add compassx

Check the minimum supported version of your project and update as necessary.

• iOS: 12
• Android: 21

Request permission to get true heading in Android. Not required on iOS.

$ flutter pub add permission_handler

Specify the permissions one or both of the following in AndroidManifest.xml. It can be copied from example.

<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />

• ACCESS_COARSE_LOCATION: Used when normal accuracy is required.
• ACCESS_FINE_LOCATION: Used when the highest quality accuracy is required.

Add code to request permissions.

if (Platform.isAndroid) await Permission.location.request();

CompassX heading currently supports only portrait mode. It is recommended to fix the orientation of the device.

SystemChrome.setPreferredOrientations([
        DeviceOrientation.portraitUp,
        DeviceOrientation.portraitDown,
      ]);

It is recommended to use a real device. iOS simulators cannot use the heading sensor (compass). See Testing CompassX for details.

If you are going to use this plugin in your product apps, I strongly suggest you read full documentation carefully.

• True Heading vs Magnetic Heading
• How to calibrate your device's compass